Types of Angles and Lines

Front

What is a right angle?

Back

An angle that forms a square corner and has a measure of 90 degrees.

Front

What are perpendicular lines?

Back

Lines that intersect to form right angles.

Front

What are parallel lines?

Back

Lines that never intersect.

Front

What is an acute angle?

Back

An angle that is open less than a right angle and has a measure less than 90 degrees.

Front

What is an obtuse angle?

Back

An angle that is open more than a right angle but less than a straight angle. This angle measures between 90 and 180 degrees.

Front

What is a straight angle?

Back

An angle that measures exactly 180 degrees.

Front

What is a reflex angle?

Back

An angle that is greater than 180 degrees but less than 360 degrees.

Front

What is the sum of angles in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees.

Front

What is a transversal line?

Back

A line that intersects two or more lines at different points.

Front

What are complementary angles?

Back

Two angles that add up to 90 degrees.